Single Use Lancet Assembly

Abstract

A single use, spring-driven lancet assembly having a housing, a removable cap, a lancet, a lancet trigger member and a spring. The lancet trigger comprises a nose that extends from the front of the housing. When the lancet assembly is pressed against the skin or vice versa, the trigger is pushed toward the rear of the housing. A pair of flexible trigger arm members in contact with cocking lugs on the lancet body push the lancet to the rear and compress the spring. As the trigger and lancet move to the rear within the housing, the flexible arm members of the trigger are spread apart and the released lancet is propelled forward. The spring recoils into a neutral position and draws the lancet and its needle back into the housing. The lancet assembly cannot be re-cocked and the lancet needle cannot be intentionally or accidentally extended from the housing.

I claim: 
     
         1 . A lancet assembly comprising:
 a housing comprising a proximal end, a distal end, a distal opening, an angled guide surface and a detention shoulder;   a cap removably mounted onto said housing and covering said distal opening;   a trigger member positioned within said housing, said trigger member comprising a nose extending through said distal opening of said housing, a body, a lancet bore extending through said nose and said body, an arm member connected to said body and extending toward said proximal end of said housing, said arm member having a free end, a detention member mounted on said free end of said arm member, and a cocking flange positioned on said arm member;   a lancet positioned within said housing and extendable through said lancet bore of said trigger member and through said distal opening of said housing, said lancet comprising a main body, a needle extending from said main body, and a cocking lug;   a spring member connected to said lancet;   wherein said trigger member and said lancet are retained within said housing in a manner allowing movement of said trigger member toward said proximal end of said housing and allowing movement of said lancet toward said proximal end and said distal end of said housing;   wherein in a pre-cocked condition said needle is positioned within said housing, and said cocking flange of said trigger member is positioned closer to said distal end of said housing than said cocking lug of said lancet;   wherein with said cap removed from said housing said trigger member may be moved toward said proximal end of said housing such that said cocking flange abuts said cocking lug, thereby moving said lancet main body toward said proximal end of said housing and loading said spring, such that said free end of said arm member is biased outwardly by said angled guide surface as said trigger member is moved toward said proximal end of said housing, such that said cocking flange is moved out of contact with said cocking lug, thereby allowing said spring to propel said lancet needle through and beyond said distal opening of said housing, and such that said detention member of said arm member is restrained by said detention shoulder of said angled guide surface, thereby preventing movement of said trigger member toward said distal end of said housing;   wherein after extension of said needle beyond said housing distal opening said spring retracts said needle into said housing, said cocking lug of said lancet now being positioned closer to the distal end of said housing than said cocking flange of said trigger member, such that said trigger member is now incapable of moving said lancet axially toward said proximal end of said housing.   
     
     
         2 . The lancet assembly of  claim 1 , wherein said housing comprises a pair of angled guide surfaces and detention shoulders, and wherein said trigger member comprises a pair of arm members and detention members. 
     
     
         3 . The lancet assembly of  claim 2 , wherein said lancet comprises a pair of cocking lugs and said trigger member comprises a pair of cocking flanges. 
     
     
         4 . The lancet assembly of  claim 1 , further comprising a needle cover removably connected to said lancet main body and covering said needle, wherein said lancet needle cover is retained by said cap such that removal of said cap from said housing results in removal of said lancet needle cover from said lancet main body. 
     
     
         5 . A lancet assembly comprising:
 a housing comprising a proximal end, a distal end, a distal opening, an angled guide surface and a detention shoulder;   a cap removably mounted onto said housing and covering said distal opening;   a lancet retained within said housing, said lancet comprising a main body, a needle extending from said main body, and a cocking lug, said lancet comprising a longitudinal axis, wherein said lancet is movable in both axial directions relative to said housing;   a trigger member positioned within said housing, said trigger member comprising a nose extending through said distal opening of said housing, a body, a lancet bore extending through said nose and said body, an arm member connected to said body and extending toward said proximal end of said housing, said arm member having a free end, a detention member mounted on said free end of said arm member, and a cocking flange positioned on said arm member, wherein said trigger member is movable in the axial direction toward said proximal end of said housing;   said lancet being disposed within said lancet bore of said trigger member;   a spring member connected to said lancet;   wherein in a pre-cocked condition said needle is positioned within said housing, and said cocking flange of said trigger member is positioned closer to said distal end of said housing than said cocking lug of said lancet;   wherein with said cap removed from said housing said trigger member may be moved axially toward said proximal end of said housing such that said cocking flange abuts said cocking lug, thereby moving said lancet main body axially toward said proximal end of said housing and loading said spring, such that said free end of said arm member is biased outwardly by said angled guide surface as said trigger member is moved toward said proximal end of said housing, such that said cocking flange is moved out of contact with said cocking lug, thereby allowing said spring to propel said lancet needle axially through and beyond said distal opening of said housing, and such that said detention member of said arm member is restrained by said detention shoulder of said angled guide surface, thereby preventing axial movement of said trigger member toward said distal end of said housing;   wherein after extension of said needle beyond said housing distal opening said spring axially retracts said needle into said housing, said cocking lug of said lancet now being positioned closer to the distal end of said housing than said cocking flange of said trigger member, such that said trigger member is rendered incapable of moving said lancet in the axial direction toward said proximal end of said housing.   
     
     
         6 . The lancet assembly of  claim 5 , wherein said housing comprises a pair of angled guide surfaces and detention shoulders, and wherein said trigger member comprises a pair of arm members and detention members. 
     
     
         7 . The lancet assembly of  claim 6 , wherein said lancet comprises a pair of cocking lugs and said trigger member comprises a pair of cocking flanges. 
     
     
         8 . The lancet assembly of  claim 5 , further comprising a needle cover removably connected to said main body and covering said needle, wherein said lancet needle cover is retained by said cap such that removal of said cap from said housing results in removal of said lancet needle cover from said lancet main body. 
     
     
         9 . A lancet assembly comprising:
 a housing comprising a proximal end, a distal end, a distal opening, a pair of angled guide surfaces and a pair of detention shoulders;   a cap removably mounted onto said housing and covering said distal opening;   a trigger member positioned within said housing, said trigger member comprising a nose extending through said distal opening of said housing, a body, a lancet bore extending through said nose and said body, a pair of arm members connected to said body and extending toward said proximal end of said housing, said arm members each having a free end, a detention member mounted on each said free end of said arm members, and a cocking flange positioned on each said arm member;   a lancet positioned within said housing and extending through said lancet bore, said lancet comprising a main body, a needle extending from said main body, and a pair of cocking lugs; and   a spring member connected to said lancet and to said housing.   
     
     
         10 . The lancet assembly of  claim 9 , wherein said detention members abut said angled guide surfaces and said cocking flanges abut said cocking lugs. 
     
     
         11 . The lancet assembly of  claim 9 , further comprising a needle cover removably connected to said lancet main body and covering said needle. 
     
     
         12 . The lancet assembly of  claim 11 , wherein said needle cover is connected to said cap in a manner such that rotating said cap relative to said housing rotates said needle cover and separates said needle cover from said lancet main body. 
     
     
         13 . The lancet assembly of  claim 9 , wherein said trigger member and said lancet are disposed within said housing such that said trigger member is movable toward the proximal end of said housing and said lancet is movable toward said proximal end and said distal end of said housing. 
     
     
         14 . The lancet assembly of  claim 13 , wherein movement of said trigger member toward said proximal end of said housing results in movement of said lancet first toward proximal end of said housing and then toward said distal end. 
     
     
         15 . The lancet assembly of  claim 14 , wherein after said lancet moves toward said distal end of said housing, said spring retracts said lancet needle into said housing by moving said lancet toward the proximal end of said housing. 
     
     
         16 . The lancet assembly of  claim 9 , wherein said trigger member, said cocking flanges, said cocking lugs, said angled guide surfaces and said arm members are disposed within said housing such that movement of said trigger member toward said proximal end of said housing results in separation of said arm members such that said cocking flanges no longer abut said cocking lugs, thereby allowing said lancet to move toward said distal end of said housing. 
     
     
         17 . The lancet assembly of  claim 16 , wherein said detention members and said detention shoulders are disposed within said housing such that said movement of said trigger member toward said proximal end of said housing results in said detention members abutting said detention shoulders, thereby preventing said trigger member from moving toward said distal end of said housing. 
     
     
         18 . The lancet assembly of  claim 15 , wherein said trigger member, said cocking flanges, said cocking lugs, said angled guide surfaces and said arm members are disposed within said housing such that said movement of said trigger member toward said proximal end of said housing results in separation of said arm members such that said cocking flanges no longer abut said cocking lugs, thereby allowing said lancet to move toward said distal end of said housing. 
     
     
         19 . The lancet assembly of  claim 18 , wherein said detention members and said detention shoulders are disposed within said housing such that said movement of said trigger member toward said proximal end of said housing results in said detention members abutting said detention shoulders, thereby preventing said trigger member from moving toward said distal end of said housing.